Blue Planet pH Down reduces alkalinity and increases acidity in aquarium water.
DIRECTIONS FOR USE: Add a sufficient quantity of pH Down to aquarium water to achieve a neutral or desired reading. Accurate pH levels can be obtained by testing the aquarium water with an pH Test Kit after the addition of pH Down until desired reading is achieved.
IMPORTANT: To avoid unduly stressing fish all pH changes should be made gradually - small changes (less than 0.5 units) over a few days. Large changes over a week.